1. Field of the Invention
The present invention pertains to an emergency engine fuel flow shut-off system operable from the driver's station and from outside the vehicle, and particularly adapted for large off-highway trucks and similar vehicles.
2. Background
Emergency engine shut-down systems are considered desirable in many internal combustion engine applications, particularly, for example, in regard to engines operating in hazardous environments in off-highway construction and mining equipment and the like. One type of engine shut-down system used on diesel engine powered off-highway haulage trucks, of a type sometimes known as dumpers, comprises a cable operated butterfly or flapper type valve which may be operated by the vehicle driver to shut off air flow to the engine. Off-highway haulage trucks, such as used in large open pit mines and similar applications, operate in an environment which is not favorable to cable-operated devices since the cable mechanism often becomes contaminated with fine dirt and dust which hinders suitable functional actuation of the cable and the engine shut-down valve. Moreover, on diesel engines in particular, if the combustion air flow to the engine is maintained at even a reduced capacity, the engine will continue to run without shut-off of fuel flow.
Still further, the operating environment of the aforementioned types of trucks, particularly in large open-pit coal mines provides a somewhat more hazardous operating environment and a stronger likelihood that an engine fire may occur from time to time on board such trucks. In this regard it is desirable to have an emergency engine shut-down system which is operable not only from the driver's station or cab but also from the ground adjacent to the driver boarding ladder in the event that the driver must exit the vehicle before having the opportunity to actuate the engine shut-off system. The foregoing considerations have resulted in an improved emergency engine shut-down system particularly adapted for off-highway dumper trucks and the like as described hereinbelow.